CVE-2026-32141 flatted: Unbounded recursion DoS in parse() revive phase
An attacker can crash the Node.js process by sending crafted JSON with deep nesting to the flatted parser, causing a stack overflow.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32141?
CVE-2026-32141 is a high-severity denial of service vulnerability in WebReflection flatted, published on 12 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
flatted is a circular JSON parser. Prior to 3.4.0, flatted's parse() function uses a recursive revive() phase to resolve circular references in deserialized JSON. When given a crafted payload with deeply nested or self-referential $ indices, the recursion depth is unbounded, causing a stack overflow that crashes the Node.js process. This vulnerability is fixed in 3.4.0.
Which versions are affected by CVE-2026-32141?
2 open source packages ship an affected version, including flatted. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
flatted npm | All versions | 3.4.0 |
flatted npm | All versions | 3.4.0 |
Products include Webreflection Flatted.
How do I fix CVE-2026-32141?
Upgrade flatted to 3.4.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-32141 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-32141 exists.
Other vulnerabilities in WebReflection flatted
Sources
Also known as AZL-80312, CLEANSTART-2026-BE82466, CLEANSTART-2026-CH50712, CLEANSTART-2026-KQ19093, CLSA-2026-1792232973, DEBIAN-CVE-2026-32141 and 9 more.